Blender 2.72 "blender-app.exe"
As @Lord Spectre said, blender.exe is a launcher to blender-app.exe.
From this thread on BlenderArtist:

When the devs moved Blender windows compilation to use mscv2013, it broke the OpenMP support for windows (that makes some functions multithreaded) (while legacy mscv2008 builds were still working good with OpenMP)
This nasty problem was noticed first in a sculpt mode report in which a simple brush stroke on even very low poly stuff was pulling CPU usage to 100% (without any actual performance gain) instead of the +/- 30 CPU use.
As a solution, the devs went with a &quot;launcher&quot; that would apparently set some variable to lower the impact of OpenMP breakage , the discussion between dev can be read on the august mailing list &quot;[Bf-committers] OpenMP issues with msvc2013 builds&quot;.